Building a mining rig advise

[gondel]

Hello,
I want to build my first mining rig by myself. Everyone is speaking about those rx480 cards and I left with the impression they are the best at the moment (speed ratio and electricity consumption). Can someone advise which rx480 exactly is the best option to invest in ( i think to buy 6 of them as start), is it worth it buying 8gb then 4gb and why? Also should I consider exactly this card for that price or there might be something better? I am willing to mine the most profitable coin, but time to time i would like to jump on something new just to give it a chance if it will goes on some exchange. The price of the electricity where I am is 10 cents so it worth start mining.
Thanks in advance!
BR
G